Field
This disclosure relates generally to integrated sensors, and more specifically, to testing and calibration.
Related Art
Inertial sensors may be used in many applications. They are typically used to detect force in one or more directions, typically forces created by moving objects such as an airplane, train, vehicle or the like. In short, anything that has a mass that can be moved to create inertial forces can typically be measured by inertial sensors. An example application of inertial sensors, is in an automotive safety systems such as air bag systems, anti lock-brakes (“ABS”), vehicle stability controls (“VSC”) and the like.
To integrate easily into an electrical system, such as found in a vehicle, inertial sensors may be in the form of electronic circuits. In such circuits, the sensor (or transducer) can be a part of a multichip and sometimes integrated solution in a package. In such electronic circuits, the electrical signal representing the force or motion may be produced by any number of methods. Typically the force measured can cause a change in some fundamental electrical parameter of the integrated circuit, such as capacitance, resistance, transistor gain, inductance, or the like.
Since movement can often occur in such circuits, as well as manufacturing variations, the sensors outputs may vary greatly, or drift during operation. In addition, mechanical forces being measured can be made up of a spectrum of mechanical frequencies. Transducers may respond to the frequencies that make up such a mechanical input signal differently from sensor to sensor. Thus, a transducer may also have a unique frequency response that may also change over time. And also, a given sensor may respond differently or fail after being used for a while. As inertial sensing applications continue to grow, the demands made upon inertial sensors will most likely call for improved and more reliable sensors, and sensor performance.